Response Of Clay-Unit Masonry To Repeated Compressive Forces

Behaviour of clay-unit masonry was found to be influenced significantly by repeated compressive forces. A total of 120 stack-bond test prisms were subjected to concentric axial forces. Amounts of sustained and alternating stress were varied as well as the mortar type. Results showed that reductions in static strengths as large as 30% were possible for as little as 40 cycles of loading at a relatively small amplitude of alternating force. Strength reductions were attributed to inelastic straining of mortar and accumulation of lateral tractions between mortar and brick.